Abstract:

A refrigerated display case is provided that includes a display chamber
for displaying product. The display chamber includes a product tray for
supporting the product. A cooling chamber is arranged beneath the product
and is in communication with a surface of the product tray. The cooling
chamber is sealed from the display chamber, in one example, and includes
a cooling coil. A fan is in communication with the cooling chamber and
cooling coil. The fan circulates a cooling flow through the cooling coil.
The cooling flow moves across the surface and absorbs heat from the
product tray by convection. The cooled product tray removes heat from the
product by conduction.

Claims:

1. A refrigerated display case comprising:a display chamber having a
product tray for supporting product, the product tray having a topside
and an underside;a cooling chamber disposed beneath the product tray;
anda fan in communication with the cooling chamber a cooling coil for
generating a flow of chilled air across the underside of the product tray
to remove heat therefrom;wherein the product tray provides a seal between
the display chamber and the cooling chamber to prevent the chilled air in
the cooling chamber from infiltrating the display chamber.

2. The refrigerated display case according to claim 1, wherein the fan
generates a horizontal flow of chilled air across the underside of the
product tray.

3. The refrigerated display case according to claim 2, further comprising
a baffle arranged in the cooling chamber, the baffle directing the flow
of chilled air across the underside of the product tray.

4. The refrigerated display case according to claim 3, wherein the fan
blows the flow of chilled air generally parallel to the baffle.

5. The refrigerated display case according to claim 3, wherein the fan
blows the flow of chilled air generally parallel to the product tray.

6. The refrigerated display case according to claim 5, wherein the cooling
coil comprises first and second coils and the baffle comprises first and
second baffles associated with the first and second coils and the fan is
arranged between the first and second coils to generate first and second
flows of chilled air in opposing directions respectively through first
and second coils and returning to the fan.

7. The refrigerated display case according to claim 1, wherein the fan and
the cooling coil are disposed within the cooling chamber.

8. The refrigerated display case according to claim 1, wherein the cooling
coil is disposed within the cooling chamber in a non-contact relationship
with the product tray and the flow of chilled air generates convection
cooling of the underside of the product tray.

9. The refrigerated display case according to claim 8, wherein the
convection cooling generates conduction cooling of product on the topside
of the product tray.

10. The refrigerated display case according to claim 1, further comprising
a gravity coil arranged in the display chamber, the gravity coil
generating cooling providing a buoyancy circulation air pattern within
the display chamber.

11. The refrigerated display case according to claim 1, further comprising
a refrigerant system that includes the cooling coil arranged within the
cooling chamber and a gravity coil arranged within the display chamber, a
refrigerant from the cooling coil and gravity coil flowing to a
compressor arranged upstream from a heat exchanger, the refrigerant from
the heat exchanger flowing to an expansion device before being received
by the cooling coil.

12. A method of providing a refrigerated display case, comprising the
steps of:separating and sealing a display chamber and a cooling chamber
from one another using a product tray, the product tray having a topside
configured to support products thereon and an underside;generating a
convection cooling on the underside of the product tray, the convection
cooling contained within the cooling chamber and configured to cool the
products with conduction cooling on the top side of the tray ;
andproviding a gravity cooling coil within the display chamber configured
to cool the products with a buoyancy circulation of chilled air from the
gravity cooling coil.

13. The method according to claim 12, comprising the step of generating a
cooling flow in a cooling chamber arranged beneath the product tray.

14. The method according to claim 13, comprising blowing the cooling flow
across a cooling coil.

15. The display case according to claim 1, wherein the cooling coil
includes fins.

16. The display case according to claim 1, wherein the display chamber
includes a display window providing visual access to the product within
the display chamber.

17. A refrigerated display case comprising:a display chamber having a
product tray for supporting one or more products thereon, the product
tray having a topside and an underside;a cooling chamber disposed beneath
the product tray and separated from the display chamber by the product
tray, the product tray defining a seal between cooling chamber and the
display chamber; andat least one cooling coil in communication with the
cooling chamber;a fan configured to generate a flow of chilled air
through the cooling coil;at least one baffle configured to direct a first
flow of the chilled air in a first direction across the underside of a
first portion of the product tray and in a second direction across the
underside of a second portion of the underside of the product tray to
remove heat therefrom, the first direction and the second direction being
substantially opposite one another.

18. The refrigerated according to claim 17 wherein the fan has a common
inlet for recirculating the flow of chilled air from the first flow of
chilled air and the second flow of chilled air.

19. The refrigerated according to claim 17 wherein the seal between the
cooling chamber and the display chamber substantially prevents
infiltration of chilled air from the cooling chamber to the display
chamber.

20. The refrigerated according to claim 17 wherein the first and second
flow of chilled air provide a first convective cooling flow within the
cooling chamber, and further comprising a gravity cooling coil arranged
within the display chamber and configured to generate a second convective
cooling flow through buoyancy circulation within the display chamber, the
first convective cooling flow and the separate convective cooling flow
being separate and exclusive from one another.

Description:

[0002]Refrigerated display cases are used to refrigerate and display
products such as meat at a grocery store. The products are displayed to
customers in a display chamber that is cooled by a gravity coil. The
gravity coil cools the product by buoyancy circulation in which the
cooled air produced by the gravity coil moves downward toward the product
as it becomes more dense. As the cooled air absorbs heat from the
product, the warmed air rises toward the gravity coil where it is again
cooled. In this manner, cooled air is circulated within the display
chamber without the use of a fan, which would undesirably dry the
product.

[0003]The product is supported on a product tray. A serpentine coil is
arranged in a cooling chamber beneath the product tray. The serpentine
coil and gravity coil are connected in series. The serpentine coil has no
fins and typically extends along the length of the display case. The
serpentine coil is not permitted to touch the product tray since its
temperature is much colder than freezing. The serpentine coil simply
removes any heat gain attributable to the lower portion of the display
case to prevent heat gain in the product. The majority of the refrigerant
load is associated with the gravity coil, which results in an unbalanced,
inefficient refrigeration system.

[0004]What is needed is a refrigerated display case that improves heat
removal from the products while balancing and reducing the overall
refrigeration load on the refrigerant system. Furthermore, it is desired
that the refrigeration system avoid drying the product.

SUMMARY OF THE INVENTION

[0005]A refrigerated display case is provided that includes a display
chamber for displaying product. The display chamber includes a product
tray for supporting the product. A cooling chamber is arranged beneath
the product and is in communication with a surface of the product tray.
The cooling chamber is sealed from the display chamber, in one example,
and includes a cooling coil. A fan is in communication with the cooling
chamber and cooling coil. The fan circulates a cooling flow through the
cooling coil. The cooling flow moves across the surface and absorbs heat
from the product tray by convection. The cooled product tray removes heat
from the product by conduction.

[0006]These and other features of the application can be best understood
from the following specification and drawings, the following of which is
a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 is a schematic, cross-sectional view of an example
refrigerated display case.

[0008]FIG. 2 is a schematic view of a refrigerant system used to cool the
display case shown in FIG. 1.

[0009]FIG. 3 is a schematic, cross-sectional view of another example
refrigerated display case.

[0010]FIG. 4 is a cross-sectional view of a portion of a cooling coil for
use in the refrigerated display case.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0011]A refrigerated display case 10 is shown in FIGS. 1 and 3. The
display case 10 includes a display chamber 12 used for supporting
products 14, such as meat.

[0012]The display chamber 12 includes a display window 16 through which
customers view the products 14. The display chamber 12 is accessible
through access panels 18 opposite the display window 16. Typically, an
air curtain device 22 that includes a fan 24 blows an air curtain A
across the display window 16 to minimize the heat transfer to the display
chamber 12 through the display window 16.

[0013]An example refrigerant system 26 is schematically shown in FIG. 2.
The refrigerant system 26 includes a gravity coil 36 (also shown in FIGS.
1 and 3) arranged in the display window 16. The gravity coil 36 cools the
products 14 by radiation thereby generating a buoyancy circulation B,
which is shown in FIG. 3. As the air display chamber 12 cools and becomes
more dense, it flows to the bottom of the display chamber 12 where it
removes heat from the products 14. As the cooled air absorbs heat, it
rises to the gravity coil 36 where it is again cooled. In this manner,
the products 14 are cooled without the use of a fan, which would
undesirably dry the products 14.

[0014]Returning to FIG. 2, the refrigerant system 26 includes a compressor
28 that receives the refrigerant from the gravity coil 36. The compressed
refrigerant flows to a heat exchanger 30 from which heat is rejected to
an outside environment. Refrigerant flows from the heat exchanger 30 to
an expansion device 32, for example, that expands thereby producing
cooled refrigerant. The expanded refrigerant flows to a cooling coil 46
before flowing to the gravity coil 36.

[0015]Typically the compressor 28 and heat exchanger 30 are located
outside the refrigerated display case 10, and the expansion device 32,
cooling coil 46 and gravity coil 36 are located within the display case
10. However, it should be understood that the components of the
refrigerant system 26 can be located in any suitable location and manner.
Moreover, one or more temperature sensors may be used to communicate
temperature information from various locations within the display case 10
to provide a feedback system and accurately refrigerate the display case
10.

[0016]Returning to FIG. 1, a cooling chamber 38 is provided beneath the
display chamber 12 and is supported by a base 20. The products 14 are
supported on a product tray 40 that separates the display chamber 12 and
cooling chamber 38. In one example, the product tray 40 seals the cooling
chamber 38 to prevent undesired air flow from entering the display
chamber 12 from the cooling chamber 30, which would undesirably dry the
products 14.

[0017]Typically, a foam barrier 42 is used at the bottom of the cooling
chamber 38 and is supported by the base 20 to minimize heat transfer from
the outside environment into the cooling chamber 38.

[0018]In the example, a fan 44 is utilized to generate a cooling flow F
within in the cooling chamber 38. The cooling flow F cools the product
tray 40 by convection, which in turn cools the products 14 by conduction.
In this manner, the cooling coil 46 operates to provide significant
cooling to the products 14 instead of simply acting as a heat sink to
prevent heat transfer to the products 14 from the bottom of the display
case 10, as in the prior art.

[0019]In one example, the cooling coils 46 include fins 48, which is shown
in FIG. 4. The fins 48 increase the heat transfer to the cooling coils 46
from the cooling flow F as it picks up heat from the products 14 through
the product tray 40. A baffle 50 is used in the example shown in FIG. 1
to guide the cooling flow F horizontally along a lower surface of the
product tray 40 (generally parallel) to maximize convection cooling to
the product tray 40.

[0020]Another example arrangement is shown in FIG. 3. In the example
shown, the fan 44 is arranged between coils 46. A baffle 50 is associated
with each coil 46. The cooling flow F moves laterally outward from the
fan 44 to the front and rear of the cooling chamber 38 before returning
through the respective coils 46. The coils 46 shown in FIG. 3 may be
parallel, lateral lengths of the same coil, for example.

[0021]Although example embodiments have been disclosed, a worker of
ordinary skill in this art would recognize that certain modifications
would come within the scope of the claims. For that reason, the following
claims should be studied to determine their true scope and content.